title: Serum thymus and activation-regulated chemokine as disease activity and response biomarker in alopecia areata.
abstract: Serum thymus and activation-regulated chemokine/CCL17 (sTARC) is known as a good indicator for atopic dermatitis severity. Herein, we investigate whether sTARC correlates with severity and therapeutic response for alopecia areata (AA) in our 121 patients. The sTARC mean of AA totalis and universalis was significantly higher than mild AA. Next, we compared sTARC of diffuse AA (n = 14) and severity-controlled patchy AA (n = 32) and found that sTARC in diffuse AA (564.2 ± 400.0 pg/mL) was significantly higher than that of the patchy type (344.0 ± 239.8 pg/mL), suggesting a potential role of TARC in active progression of diffuse AA. Ten patients with diffuse AA were treated with i.v. corticosteroid pulse therapy. Then, we tested whether sTARC can predict prognosis after the pulse therapy and found that baseline sTARC in the poor responders (1025.5 ± 484.8 pg/mL) was significantly higher than that in the good responders (complete remission at 24 months after the pulse therapy, 347.8 ± 135.7 pg/mL), indicating sTARC as a response biomarker in the corticosteroid pulse therapy for diffuse AA. Finally, to investigate TARC production in the affected hair follicles, we performed immunohistochemical double staining of TARC and CD68 using scalp skin specimens of diffuse AA with high titers of sTARC. The results showed their co-localization in the infiltrating cells around the AA hair follicles, suggesting that TARC is mainly produced from CD68(+) histiocytes. In conclusion, sTARC is a disease activity and response biomarker in AA, providing new insight beyond the T-helper 1/2 paradigm to solve the immunological pathogenesis of AA.
authors.affiliation: Department of Regenerative Dermatology, Osaka University Graduate School of Medicine, Suita, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Inui
authors.forename: Fumihito
authors.initials: F
authors.lastname: Noguchi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nakajima
authors.forename: Satoshi
authors.initials: S
authors.lastname: Itami
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000506:Alopecia Areata / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D054414:Chemokine CCL17 / Q000097:blood*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D015415:Biomarkers; C106230:CCL17 protein, human; D054414:Chemokine CCL17
keywords: CD68; alopecia areata; atopic dermatitis; i.v. corticosteroid pulse therapy; thymus and activation-regulated chemokine/CCL17